Solid state control circuit for vending devices

ABSTRACT

A solid state control circuit for use in controlling vending devices is disclosed. The control circuit permits any one of a plurality of individual items to be selected from a quantity of merchandise stored in a vending device while minimizing the risk that prospective purchasers will lose money in the device due to the existence of a sold-out condition and/or a mechanical malfunction. The control circuit includes a plurality of feedback networks for automatically resetting it upon selection of a particular item, and also includes lock-out networks so that the vending device will not accept coins if all selections are sold out, and/or if the vending stages become jammed during their vending cycles. The control logic is highly versatile, can be adapted to control machines with any number of vending selections, and can also be adapted to control multiple price sales.

United States Patent 1 [111 3,891,075

House 1 June 24, 1975 SOLID STATE CONTROL CIRCUIT FOR VENDING DEVICES Primary Examiner-R0bert B. Reeves Assistant E.\'aminerThomas E. Kocovsky Attorney, Agent, or Firm-Gerald K. Kita [75] Inventor: William James House, Harrisburg,

Pa. [73] Assignee: AMP Incorporated, Harrisburg, Pa. [57] ABSTRACT A solid state control circuit for use in controlling [22] Flled: 1973 vending devices is disclosed. The control circuit per- [21] Appl. No.: 415,039 mits any one ofa plurality of individual items to be selected from a quantity of merchandise stored in a vending device while minimizing the risk that prospec- [52] US. Cl [94/9 R five purchasers will lose money in the device due to [5 It. CI. the existence sold out Condition and/or a mechan [58] held of Search 194/ l 9 10 ical malfunction; The control circuit includes a plurality of feedback networks for automatically resetting it upon selection of a particular item, and also includes 1 References C'ted lock-out networks'so that the vending device will not UNITED STATES PATENT accept coins if all selections are sold out, and/or if the 3,478,855 11/1969 Seversen 194/9 R ending stages become jammed during their vending 3,486,601 12/1969 Bowman 194/10 cycles. The control logic is highly versatile, can be 3,589,492 1/1971 Shirley 194/10 adapted to control machines with any number of 3.703.22 1 1972 Bowling H 194/ 10 vending selections, and can also be adapted to control 3,756,364 9 1973 Bookholt 194/10 multiple prim sales. a

8 Claims, 3 Drawing Figures DC. A.C POWER 1. F 7

MASTER CONTROL SELECT SWITCH NAND SOLD COIN REJECT INHIBIT NAND 3%, ELECTROMAGNETS NOR DC AC ow it NAND F. F. 1L f l I l L MOTOR 0 T DC AC SOLID STATE CONTROL CIRCUIT FOR VENDING DEVICES BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to controlled circuitry, and more particularly to a solid state control circuit for vending devices.

2. Description of the Prior Art As automated vending devices become more and more common, it has become increasingly important to upgrade their performance. Unfortunately, in the past many common vending machines had a tendency to jam or freeze in the course of a vend cycle so that customers lost money in the machines, and were unable to obtain the goods they desired to purchase. Furthermore, even after such machines jammed, they would still accept coins from prospective purchasers, so that large numbers of prospective buyers could'lose money in the same machine. Such machines, by pilfering from the public, created an atmosphere of bad will toward the machine owners and toward the products being dispensed among those who had unwillingly lost money in the machines. In some cases this bad will has motivated frustrated purchasers to engage in physical damage to, and destruction of, certain vending machines. In these cases the vending machine owners lost not only potential sales of their goods, but also suffered substantial losses due to the damage wrought to their machines. Accordingly, there is a need to improve vending machine operation to minimize such pilferage from the public and to minimize the bad will created by vending machine malfunctions.

In addition to the problems caused by machine malfunctions, described above, vending machines available in the past have often lacked the advantages afforded by modern control circuitry. More particularly, many vending machines control circuits available in the past were incapable of the type of rapid operation which is possible with modern solid state circuitry. Furthermore, the most common vending machine control circuits previously available lacked the reliability, low cost and ease of repair which are presently attainable with modern circuit components. In addition, the control circuits utilized in the past often lacked the versatility that can now be achieved with ease using solid state logic networks.

Accordingly a need exists for a vending machine control circuit of improved versatility which is capable of economical manufacture and ease of installation in all types of vending devices.

SUMMARY OF THE INVENTION Accordingly, one object of this invention is to provide a novel control circuit for use with various types of vending devices.

Another object of this invention is the provision of a novel solid state control circuit which is economical to manufacture and highly reliable in operation.

Yet another object of this invention is the provision of a modern. high speed logic network for use in controlling vending devices.

A still further object of this invention is the provision of a novel circuit for controlling vending machines which provides for immediate reset upon selection of a desired purchase.

Yet another object of this invention is to provide a unique control circuit employing a plurality of feedback loops for use in controlling vending devices.

Yet another object of this invention is the provision of a unique vending machine control circuit including a lock-out provision for preventing the insertion of coins when all the positions ofa vending device are sold out and/or jammed.

Another object of this invention is the provision of a unique control circuit for vending machines which minimizes the monetary loss by the public when such machines malfunction.

Briefly, these and other objects of the invention are achieved by providing an all solid state control circuit including an AC to DC pulse converter controlled by a conventional coin changer mechanism. A master control logic network is driven by the AC to DC pulse converter for controlling a coin reject electromagnet relay and for controlling the energization of a plurality of article vending stages. Each article vending stage includes a feedback network for driving a vend motor upon selection of the particular stage, and for automatically resetting the stage and the master control logic network to a stand-by condition once a particular article has been selected for purchase. Additional logic and feedback networks are provided to ensure that the vending machine will not accept coins when the positions are all jammed in a vend condition and/or when all items are sold out.

BRIEF DESCRIPTION OF THE DRAWINGS A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the detailed description when considered in connection with the accompanying drawing, wherein:

FIGS. 1A and 18 comprise a schematic diagram of a preferred embodiment.

FIG. 2 is a block diagram of the embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawing, wherein like reference numerals designate identical or corresponding parts, a preferred embodiment of the control circuit of the present invention is illustrated in schematic form. The control circuit includes a pair of power input lines 10 and 12 which are coupled to a conventional source of l 10 volt alternating current 14. The power input line 10 is coupled to terminal number 1 of a conventional connector structure 16. The connector structure 16 is preferably a portion of a conventional coin receiving mechanism of any type know to those skilled in the art. For example, the coin receiving mechanism may be a coin changer for returning to a prospective customer an amount of change corresponding to the difference between the value of coinage inserted into a vending machine and the price of an item to be purchased. Other types of coin receiving mechanisms may equivalently be used. The connector structure 16 includes two portions 18 and 20, representing upper and lower surfaces, for example, which are interconnected such that each of the eight terminals in one portion is connected directly to the correspondingly numbered terminal in the other portion of the connector structure. Thus for example the terminal number 1 in connector portion 18 is directly coupled to terminal number 1 of connector portion 20.

The normally closed contacts of a conventional single pole, double throw coin switch 22 are coupled between terminals 1 and 7 of the connector structure 16. The coin switch 22 may be any well known coin switch of the type commonly used in vending machines wherein the switch is not activated until a sufficient quantity of coinage is inserted into the machine, whereupon the eoin switch closes. Upon closure of the coin switch, the power input line 10 is coupled through ter minal number 3 of the connector structure 16 to a transformer 24 for supplying power to a pulse converter 26. Within the pulse converter 26, the transformer 24 is coupled through a rectifier 28 and a filter circuit 30 to a relay driving coil 32. The relay driving coil 32 drives a grounded relay arm 34 between two contacts 36 and 38 which are coupled through lines 46 and 42 to various components of a master control logic network 44. The master control logic network 44 includes a two input NAND gate 46, coupled at its input to line 42 and at its output through an inverter 48 to a NOR gate 50. The output of NOR gate 50 is coupled to select line 52 and through a buffer 54 to a solid state relay 56. The solid state relay 56, as well as the other solid state relays to be described hereinafter, are preferably zero cross-over solid state relays of the type produced by Crydom Controls Division of International Rectifier Corporation as part No. D1202. Naturally, other types of equivalent solid state relays may also be used.

The output of NOR gate 50 is also coupled to one input of NAND gate 58, which is coupled at its output through an inverter 60 to one input terminal of a NOR gate 62. The line 46 coupled to contact 36 supplies the other input to NOR gate 62. The output of NOR gate 62 is coupled to one input each of NAND gates 64 and 46. The output of NAND gate 64 is coupled through an inverter 66, a NAND gate 68 and a second inverter 70 to a second solid state relay 72. A connecting line 74 connects the output of NOR gate 62 with the inputs of NAND gate 46 and NOR gate 50.

The logic components forming the master control logic network 44 function together to form a bistable latching circuit which may assume one of two stable conditions. The first of these stable conditions is called the stand-by condition, and is the condition normally assumed by the master control logic network 44 when the coin switch 22 is not activated. In this condition the NAND gates 46, 64 and 68 are enabled, resulting in an enabling signal being applied to solid state relay 72. [n this condition, the coin reject electromagnets 76, which are coupled through the terminals 2 and 6 of the connector 16 to solid state relay 72, are energized. The coin reject electromagnets are part of conventional coin receiving mechanisms commonly used on vending machines, and function to control a coin chute so that coins inserted into a vending machine are either directed to the coin switch 22, or are returned directly to the customer. In the circuit of the present invention, when the master control logic network 44 is in its stand-by condition, and the solid state relay 72 is energized, the coin reject electromagnets are energized so that coins can be accepted and will be directed to the coin switch 22. Thus in this condition a customer can insert coins into a vending machine controlled by the circuit of the present invention for the purpose of making a purchase.

Attention is now directed to a pair of article vending stages 78 and 80 which are coupled to the master control logic network 44. The article vending stages are substantially identical in structure, so that it is necessary to describe the operation of only one of the stages to permit complete understanding of the circuit of the present invention. It is further noted that although two article vending stages are shown in the drawings, substantially any number of identical stages can be added without difficulty, as will be explained in detail hereinafter.

Referring now to article vending stage 78, it is noted that this stage includes a select NAND gate 82, one input of which is coupled to the select line 52 which originates in the master control logic network 44. The other input to select NAND gate 82 is coupled to a manually operated select switch 84, which is preferably located at a convenient position in front of a vending machine and is the switch which is depressed by a prospective purchaser to select a particular item from the machine. The select switch 84 normally grounds one input of the select NAND gate 82, maintaining the gate in a disabled state. However, upon depression of the select switch 84, a positive voltage is applied to the input of the select NAND gate and this positive signal, in cooperation with an appropriate positive signal on the select line 52, enables the select gate 82.

The output of select NAND gate 82 is coupled through an inverter 86 to one input of an inhibit NAND gate 88. One contact 90 of a sold-out switch 92 is coupled to a second input of the inhibit NAND gate 88. A second contact 94 of the sold-out switch 92 is coupled through a line 96 and a buffer 98 to a solid state relay 100, which as noted above may be identical to solid state relays 56 and 72. The solid state relay 100 controls an indicator light 102 which functions to designate any vending selections which have become exhausted. in operation, the sold-out switch 92 is mounted in a vending machine to engage the articles stored in a particular magazine. The sold-out switch is normally in the position illustrated in the FIGURE, whereby it applies a ground signal to the solid state relay 100, maintaining the indicator light 102 in an inactive condition, and si multaneously permitting a positive voltage to be applied to one input of the inhibit NAND gate 88. When the articles in the magazine are exhausted, however, the sold-out switch 92 is moved from engagement with contact 94 into engagement with contact 90, whereby the indicator light 102 is activated and a ground signal is applied to the inhibit NAND gate 88, preventing any signals from being passed through the NAND gate.

The output of inhibit NAND gate 88 is passed through a diode 104 and an inverter 106 to the inputs of a reset NAND gate 108 and a NOR gate 110. The diode 104 acts as a time delay to permit activation of the vend motor circuit prior to resetting of the master control logic network, as will become apparent from the following discussion. Although the diode 104 is shown coupled between the output of inhibit NAND gate 88 and the input of inverter 106, it can also be coupled between the output of inverter 106 and the input of reset NAND gate 108.

The output of NOR gate 110 is coupled through an inverter 112 to one contact 114 ofa transfer switch 116 and to one input of a NAND gate 118. A common terminal 120 ofthc transfer switch 116 is coupled to a second input of NAND gate 118 and is also coupled through an inverter 122 to both a third input of inhibit NAND gate 88 and one input ofa NOR gate 126. NOR gate 126 is coupled in a flip-flop configuration with a second NOR gate 128, so that the output of each ofthe NOR gates is coupled to the input of the other NOR gate. The output of NAND gate 118 is coupled through an inverter 130 to one input of NOR gate 128. The output of NOR gate 126 is coupled through a feedback line 132 to one input of NOR gate 110, Similarly, the output of NOR gate 128 is coupled through a feedback line 134 to a contact 136 of transfer switch 116.

The armature of the transfer switch 116 is coupled mechanically, as designated by a dashed line 138, to a vend motor 140. The transfer switch 116 is preferably a conventional snap acting switch, and the mechanical coupling between the snap acting and the vend motor 140 is preferably in the form of a cam, so that the motor 140 actuates the transfer switch 116 as the motor rotates.

A line 142 couples both the common terminal of transfer switch 116 and the input to both NAND gate 118 and inverter 122 to a solid state relay 144 through a buffer 146. Again, the solid state relay 144 may be identical with the other solid state relays illustrated in the FIGURE.

A resetting signal is applied to the master control logic network 44 through a first feedback network from the output of reset NAND gate 108, which is coupled through an inverter 148 to the input of a reset NOR gate 150, and thence to the inputs of both NAND gates 58 and 64.

A second feedback network is provided for preventing loss of money in the vending machine due to the fact that all items are sold out or due to jamming of the mechanism during a vend operation. This feedback network includes a NOR gate 152, one input of which is coupled through a line 154 to the sold-out switch 92, and the other input of which is coupled through a line 156 to the common terminal 120 of transfer switch 116. The output of NOR gate 152 is coupled through an inverter 158 to the input of a NAND gate 160. The output of NAND gate 160 is coupled through a line 162 to an input of NAND gate 68 in the master control logic network. A second NOR gate 164 is coupled through an inverter 166 to the other input of NAND gate 160. The inputs of NOR gate 164 are coupled through lines 167 and 168 to the article vending stage 80, the components of which are identical to those of article vending stage 78, which have been described in detail. Accordingly, it is believed that those skilled in the art will immediately realize that the NOR gate 164 functions in exactly the same relationship with regard to article vending stage 80 as does NOR gate 152 with respect to article vending stage 78.

OPERATION In operation, the master control logic network 44 is normally in the stand-by condition described above. In other words, the NAND gate 68 is enabled causing actuation of the solid state relay 72, whereby the coin reject electromagnets 76 are actuated so that the vending machine can accept coins. When a customer inserts a sufficient amount of coinage into the vending machine, the coin switch 22 is tripped causing encrgization of the pulse converter 26. Energization ofthe pulse converter 26 causes the relay arm 34 to momentarily move from contact 36 to contact 38, reversing the polarity of these two contacts and applying a pulse to the master control logic network 44 for changing the-condition of the mas- 5 ter control logic from a stand-by condition to a credit established condition. In this condition the NAND Gate 68 is disabled, deactivating the solid state relay 72 and the coin reject magnets 76, so that the vending machine will not accept additional coinage. Simultaneously, a positive voltage appears at the output of NOR gate 50, enabling NAND gate 58 and solid state relay 56. The solid state relay 56 energizes an indicator light 166 which provides the opional function of suggesting a particular item for sale. In practice, the suggested selection light is simply an indicator light, or equivalent device which highlights a particular item, thereby tending to induce prospective purchasers to select that item. Accordingly, it should be emphasized that the suggested selection indicator, including buffer 54, solid state relay 56 and indicator light 166 are optional, and may be omitted without effecting the operation of the remain-ing components of the circuit of the present invention.

A more important function resulting from the positive signal at the output of NOR gate 50 is the fact that this positive signal is carried by select line 52 to the select NAND gate in each of the article vending stages. Again it is pointed out that while only two article vending stages 78 and 80 are illustrated in the FIGURE any number of identical stages can be coupled together. Each such stage would then have a NAND gate equivalent to NAND gate 82 having one input thereof coupled to select line 52. The other input of each such NAND gate is coupled to a select switch identical to that illustrated at 84. As noted above, when a prospective purchaser actuates the select switch 84, a positive signal is applied to one input of select NAND gate 82. This signal enables the select NAND gate 82 causing a positive signal to be applied to the middle input of inhibit NAND gate 88. At this time a positive signal is also applied to the upper input of inhibit NAND gate 88, assuming that the item selected by the prospective purchaser is not sold out, since in this case the sold-out switch 92 will be in'the position shown in the FIGURE so that the contact 90 is not grounded. Furthermore, a positive signal will be applied to the lower input of inhibit NAND gate 88 since a positive output will, at this time, be generated by the inverter 122. To summarize the operation of the circuit described thus far, a prospective purchaser inserts coins into the vending machine causing the select line 52 to be energized. The prospective purchaser then actuates the select switch 84 thereby initiating the vending cycle, assuming the item selected has not been sold out.

The vending cycle begins as soon as the selection cycle, described above, results in the enabling of inhibit NAND gate 88 by applying positive signals to the three inputs of this NAND gate. The output of the inhibit NAND gate 88 is delayed slightly as it passes through diode 104 so that the vend motor circuit can be actuated before the system is reset. The delayed signal passing through diode 104 is inverted and applied to one input of reset NAND gate 108 and also to one input of NOR gate 110. The output of reset NAND gate 108 is passed through inverter 148 and reset NOR gate 150 to the inputs of NAND gates 58 and 64 in the master control logic network 44, causing resetting of the master control logic to its stand-by condition. Thus the vending machine is prepared to accept additional coinage and to undergo further sales transactions. Meanwhile, the output of NOR gate 110 is passed through inverter 112 to one input of NAND gate 118 and also to contact 114 of transfer switch 116. Power is supplied from contact 1 14 though the common terminal 120 of trans fer switch 116 to line 142 to trigger solid state relay 144 for driving vend motor 140. The signal passing through contact 114 also passes through inverter 122 to NOR gate 126, causing the flip-flop comprised of NOR gates 126 and 128 to change state resulting in a sustained feedback signal along line 132 for keeping the vend motor in an operating condition. As the vend cycle terminates, the vend motor mechanically drives the armature of the transfer switch 116 into engagement with contact 136, whereby the flip-flop circuit is reset. The transfer switch then snaps back to its original position in engagement with contact 114, completing the vend cycle. As noted above, as soon as the vending cycle of a particular article vending stage begins, the master control logic network 44 is reset so that vending in other stages can be carried out while vending in the selected stage is in progress, although further selection of that stage during the vending operation is not possible. At the cessation of a vending operation, however, the selected stage and all other inactive stages are ready to begin subsequent vending operations.

Having described the vending operation, which is identical for all stages, attention is now directed to several lock-out features of the present invention which prevent coins from being inserted and lost in a machine when the machine is all sold out or in an inoperative condition.

An important feature of the several lock-out features is the lock-out feature of inhibit NAND gate 88. Whenever a stage is vending, the power supplied at contact 120 of switch 116 causes the output of inverter 122 to go to zero. This zero signal is fed by a connecting line 172 to the bottom gate of inhibit NAND 88 therefore preventing further selection of the particular stage until contact 120 of switch 116 has been normalized (by action of the mechanically linked cam operative at the end of the vending cycle) back to contact 114.

When all items in the vending machine are sold out, the armatures of the sold out switches 92 move out of engagement with contacts 94 and into engagement with contacts 90. As a result, a positive output signal is applied to lines 154 and 167, enabling NOR gates 152 and 164, respectively, and subsequently enabling NAND gate 160. The output of NAND gate 160 is a logical zero, and is applied over line 162 to NAND gate 68, disabling this gate. The output of NAND gate 68 thus causes solid state relay 72 to be inactivated, releasing the coin reject electromagnets 76 thereby preventing coins from being accepted by the vending machine. It is noted that the sold out switches 92 also activate the sold out lights 102 in each vending stage. Accordingly the logic network including NOR gates 152 and 164 and NAND gate 160 prevents loss of money in a vending machine when all items in the machine are sold out.

In addition to being sold out, another situation which occassionally occurs in vending machines and results in loss of money is jamming of the machine during a vending cycle. Jamming of the vend mechanism most often occurs in machines for vending refrigerated items wherein the vending mechanism can occasionally freeze under unusual circumstances. Mechanical failures and jammed merchandise can also result in incomplete vending cycles. Further. to prevent loss of coinage due to an incomplete vending cycle caused for any reason, the present invention includes a second set of lines 156 and 168 leading from transfer switches 116 to NOR gates 152 and 164, respectively. The lines 156 and 168 carry a positive signal when the armatures of the individual transfer switches are in engagement with contacts 114 or 136. Thus if all vending stages in the machine should become jammed due to some malfunction, the lines 156 and 168 will enable the NOR gates 152 and 164, causing NANDgate 160 to be enabled, again disabling NAND gate 68 and releasing the coin reject electromagnets so that no additional coinage will be accepted by the vending machine. Naturally, the person whose coinage is in the machine at the time when the malfunction takes place will lose his money. But the interlock circuit including NAND gate 160 prevents any further loss of coinage after the jam or malfunctions have taken place.

The circuit illustrated in the FIGURE also prevents the loss of additional coinage if each vending stage is rendered inoperative by either the fact that all merchandise is sold out and/or the fact that an incomplete vending cycle has occurred. For example, if article vending stage 78 is sold out, a positive signal will be applied to NOR gate 152 over line 154. If article vending stage becomes jammed, a positive signal will be applied over line 168 to NOR gate 164. As a result, the two NOR gates 152 and 164 will be enabled, causing NAND gate 160 to be enabled, again resulting in release of the coin reject electromagnets. This it is apparent that any combination of sold out and jammed stages will again prevent loss of coinage in the machine.

It will be apparent to those skilled in the art that the abovedescribed circuitry for preventing loss of coinage is activated only if all vending stages in the machine are rendered inoperative by jamming or because they are sold out. If only one stage remains operative the NAND gate 160 will not be enabled, and the coin reject magnets will not be released. Accordingly, the vending machine will accept coinage, but only the remaining operative vending stages can be actuated.

It is noted that any number of vending stages identical to those illustrated at 78 and 80 can be added to the illustrated circuit. However, for each added stage the NOR gate and the NAND gate must be replaced by equivalent gates having the same number of inputs as there are vending stages in the circuit. An additional NOR gate of the type illustrated at 152 and 164 must also be added for each additional vending stage. However, other than these simple modifications identical vending stages can be added without in any way changing the remaining portions of the circuit.

It is further noted that the illustrated circuit is shown using positive logic. It will be apparent to those skilled in the art, however, that conventional negative logic can be substituted for the illustrated positive logic without in any way changing the functions performed by the circuit.

The circuit of the present invention can also be modified to vend articles of different prices. In producing a multiple price system, it is merely necessary to replace the three input inhibit NAND gates 88 with four input NAND gates. The fourth input of these NAND gates is coupled to a price matrix 170, which is preferably the conventional type of price matrix included in conventional commercially available coin changing apparatuses. More than two different prices can be used, where desired, although in such cases it is necessary to provide at least some of the inhibit NAND gates 88 with an additional number of inputs, depending upon thenumber of prices desired.

It is noted that a further protective feature is provided in the present invention in the wiring arrangement of the connector structure 16. As shown in the drawings, all AC current activity is controlled by the coin switch 22. As shown in the drawings, the AC line is not reconnected to the circuit until the coin switch returns to its normally closed position. This prevents some types of theft from a vending machine. For example, if a person cemented a piece of string to a coin, inserted the coin into a vending machine, and subsequently attempted to retrieve the coin after a vending cycle had been initiated, the circuit illustrated in the FIGURE would prevent operation of the vending machine, thereby preventing a theft of merchandise from the machine.

Obviously, numerous additional modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described herein.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

l. A solid state control circuit for vending devices comprising:

a coin changer mechanism including a coin actuated switch,

an AC to DC pulse converter coupled to and controlled by said coin actuated switch,

a bistable latch circuit having first and second stable states coupled to said AC to DC pulse converter and switchable between said first and second stable states in response to pulses from said AC to DC pulse converter,

a first relay coupled between said coin changer mechanism and said bistable latch circuit for selectively enabling and disabling said coin changer mechanism in response to signals from said bistable latch circuit,

a plurality of article vending stages coupled to said bistable latch circuit,

an article selection switch in each article vending stage,

a two input logic gate in each article vending stage having one input coupledto said bistable latch circuit and one input coupled to said article selection switch whereby said two input logic gate generates an enabling output upon receiving inputs from both said bistable latch circuit and said article selection switch,

a vend motor control circuit coupled to said two input logic gate for activation upon receipt of said enabling output therefrom,

a first feedback circuit coupled between each of said article vending stages and said bistable latch circuit for resetting said latch circuit; and,

. 6 a second fecdbackcircuit coupled between each of said article vending stages and said coin changer mechanism for rendering said coin changer mechanism inoperative upon detection of a predetermined condition in each of said vending stages.

2. A solid state control circuit for vending devices as in claim 1, wherein said vend motor control circuit includes:

an inhibit gate coupled to said two input logic gate at its input and to said first-feedback circuit at its ouotput,

a vend motor control relay,

a vend motor coupled to said vend motor control rea transfer switch electrically coupled to said inhibit gate and to said vend motor control relay and mechanically coupled to said vend motor; and,

a flip-flop circuit coupled to said vend motor control relay for maintaining said vend motor in an operative state for a predetermined interval, and coupled to said transfer switch to be reset thereby after said predetermined interval.

3. A solid state control circuit for bending devices as in claim 3, further comprising:

a sold-out switch in each of said article vending stages for indicating that particular items are soldout; and wherein said second feedback circuit is coupled to each of said sold-out switches and to said transfer switch for rendering said coin changer mechanism inoperative when said article vending stages are sold-out or jammed.

4. A control circuit for a vending device comprising:

a pulse generator in the form of an AC to DC pulse converter for generating an activating signal in response to detection of a predetermined mechanical stimulus,

master control logic network means including first and second logic gates coupled to said pulse converter for switching from a first stable state to a second stable state in response to generation of said activating signal,

vending stage control means coupled to said master control logic network means for controlling the dispensing of items from said vending device, said vending stage control means being disabled when said master control logic network means is in said first stable state and enabled when said master control logic network means is in said second stable state,

first feedback means coupled between said vending stage control means and said master control logic network means for resetting said master control logic network means from said second stable state to said first stable state upon operation of said vending stage control means,

second feedback means coupled between said vendmaster control logic network means coupled to said input means for switching from a first stable state to a second stable state in response to generation of said activating signal,

a manually operable selector switch means coupled to said master control logic network means for selection of a particular dispensed item and for controlling the dispensing of an item from said vending device, said selector switch means being disabled by said master control logic network means in said first stable state and enabled by said master control logic network means in said second stable state,

an article vending motor,

vending motor control relay means coupled to said selector switch means for operating said motor,

motor control circuit means coupled to said control relay means and said selector switch means for controlling the operation of said control relay means,

first feedback means coupled between said selector switch means and said master control logic network means for resetting and master control logic network means from said second stable state to said first stable state upon operation of said selector switch means,

second feedback means coupled between said selector switch means and said input means for rendering said input means inoperative in response to selected conditions existing in said selector switch means,

a plurality of input logic gate means coupled to said master control logic network means and to both said selector switch means and said control relay means for generating and enabling output to said control relay means and said selector switch means upon the occurence of a predetermined combination of signals from said plurality of input logic gate means,

a flip-flop circuit coupled to said plurality of input logic gate means and triggered by said enabing output, and

a switch coupled to said flip-flop circuit and said motor,

said motor being mechanically coupled to said switch for mechanically actuating said switch and resetting said flip-flop.

6. A control circuit as in claim 5, wherein:

said first feedback means includes a NOR gate coupled to the output of said multiple input logic gate.

7. A control circuit for a vending device comprising:

input means for generating an activating signal in response to detection of a predetermined mechanical stimulus,

master control logic network means coupled to said input means for switching from a first stable state to a second stable state in response to generation of said activating signal,

vending stage control means including a plurality of substantially identical vending control circuits coupled to said master control logic network means for controlling the dispensing of items from said vending device, said vending stage control means being disabled when said master control logic network means is in said first stable state and enabled when said master control logic network means is in said second stable state,

first feedback means coupled between said vending stage control means and said master control logic network means for resetting said master control logic network means from said second stable state to said first stable state upon operation of said vending stage control means,

second feedback means coupled between said vending stage control and said means,

second feedback means including a first switch means in each of said vending control circuits rendering said input means inoperative when items in said vending device are sold out,

second switch means in each of said vending control circuits for rendering said input means inoperative during the occurence of a vending cycle,

each said vending control circuits having a first logic gate coupled to corresponding first and second switches of said vending control circuit,

each said vending control circuit having a second logic gate coupled to each first logic gate and to said input means for rendering said input means inoperative upon generation of appropriate combination of outputs from said switches.

8. A solid state circuit for a vending device having a plurality of vending stations, comprising:

electromagnetic means for preventing insertion of a 25 coin into said vending device when all the vending stations are sold out or jammed,

each vending station having a sold-out switch and a manually operable select switch and a vend motor and a drive circuit for the vend motor,

each vending station having a first gate coupled to a corresponding select switch and a corresponding sold-out switch,

a master control logic network coupled to each first gate and being coin activated to a first stable state sending an enabling signal to each first gate,

each'first gate being coupled to a drive circuit of each vending station,

each said select switch being manually actuable to send an enabling signal to a corresponding first gate,

each first gate being enabled by said logic network and a corresponding select switch to enable a corresponding drive circuit and to operate a corresponding vend motor,

a unistable transfer switch in a first stable state connecting a corresponding drive circuit to a corresponding vend motor, the output of each vend motor being connected to a corresponding transfer switch,

each transfer switch being thrown to an unstable state by operation of a corresponding vend motor to reset said corresponding drive circuit of an operating vent motor,

each said transfer switch automatically resetting to its first stable state at completion of a vend cycle,

each first gate receiving an inhibit signal from a corresponding sold-out switch activated because of an empty vend station,

each sold-out switch being coupled to said electromagnetic means to activate said electromagnetic means when all the sold-out switches are activated to prevent insertion of a coin into said vending machine, and

each transfer switch being coupled to said electromagnetic means and maintaining said electromagnetic means activated when all the transfer switches are in a jammed condition between their unstable and stable state to prevent insertion of a coin into said vending machine.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,891,075

DATED June 24, 1975 INVENTOR( I William James House It is certified that error appears in the ab0ve-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 10, Claim 2, line 8, "ouotput" shouldbe -output-.

Column 11. Claim 5, line 22, omit "and" and insert -said-;

Column 12, Claim 7, line 8, after "control" insert ---means-; same line, after "said" insert -input-.

Column 12, Claim 7, line 9, insert the word -saidbefore "second".

Signed and Sealed this Attest:

RUTH C. MASON Arresting Officer C. MARSHALL DANN Commissioner oj'Patents and Trademarks 

1. A solid state control circuit for vending devices comprising: a coin changer mechanism including a coin actuated switch, an AC to DC pulse converter coupled to and controlled by said coin actuated switch, a bistable latch circuit having first and second stable states coupled to said AC to DC pulse converter and switchable between said first and second stable states in response to pulses from said AC to DC pulse converter, a first relay coupled between said coin changer mechanism and said bistable latch circuit for selectively enabling and disabling said coin changer mechanism in response to signals from said bistable latch circuit, a plurality of article vending stages coupled to said bistable latch circuit, an article selection switch in each article vending stage, a two input logic gate in each article vending stage having one input coupled to said bistable latch circuit and one input coupled to said article selection switch whereby said two input logic gate generates an enabling output upon receiving inputs from both said bistable latch circuit and said article selection switch, a vend motor control circuit coupled to said two input logic gate for activation upon receipt of said enabling output therefrom, a first feedback circuit coupled between each of said article vending stages and said bistable latch circuit for resetting said latch circuit; and, a second feedback circuit coupled between each of said article vending stages and said coin changer mechanism for rendering said coin chanGer mechanism inoperative upon detection of a predetermined condition in each of said vending stages.
 2. A solid state control circuit for vending devices as in claim 1, wherein said vend motor control circuit includes: an inhibit gate coupled to said two input logic gate at its input and to said first feedback circuit at its ouotput, a vend motor control relay, a vend motor coupled to said vend motor control relay, a transfer switch electrically coupled to said inhibit gate and to said vend motor control relay and mechanically coupled to said vend motor; and, a flip-flop circuit coupled to said vend motor control relay for maintaining said vend motor in an operative state for a predetermined interval, and coupled to said transfer switch to be reset thereby after said predetermined interval.
 3. A solid state control circuit for bending devices as in claim 3, further comprising: a sold-out switch in each of said article vending stages for indicating that particular items are sold-out; and wherein said second feedback circuit is coupled to each of said sold-out switches and to said transfer switch for rendering said coin changer mechanism inoperative when said article vending stages are sold-out or jammed.
 4. A control circuit for a vending device comprising: a pulse generator in the form of an AC to DC pulse converter for generating an activating signal in response to detection of a predetermined mechanical stimulus, master control logic network means including first and second logic gates coupled to said pulse converter for switching from a first stable state to a second stable state in response to generation of said activating signal, vending stage control means coupled to said master control logic network means for controlling the dispensing of items from said vending device, said vending stage control means being disabled when said master control logic network means is in said first stable state and enabled when said master control logic network means is in said second stable state, first feedback means coupled between said vending stage control means and said master control logic network means for resetting said master control logic network means from said second stable state to said first stable state upon operation of said vending stage control means, second feedback means coupled between said vending stage control means and said input means for rendering said input means inoperative in response to selective conditions existing in said vending stage control means, and solid state relay means coupled to said first and second logic gates and to said input means for rendering said pulse generator insensitive to said predetermined mechanical stimulus upon receiving an appropriate signal from said first and second logic gates.
 5. A control circuit for a vending device, comprising: input means for generating an activating signal in response to detection of a predetermined mechanical stimulus, master control logic network means coupled to said input means for switching from a first stable state to a second stable state in response to generation of said activating signal, a manually operable selector switch means coupled to said master control logic network means for selection of a particular dispensed item and for controlling the dispensing of an item from said vending device, said selector switch means being disabled by said master control logic network means in said first stable state and enabled by said master control logic network means in said second stable state, an article vending motor, vending motor control relay means coupled to said selector switch means for operating said motor, motor control circuit means coupled to said control relay means and said selector switch means for controlling the operation of said control relay means, first feedback means coupled between said selector switch means and said master control logic network means for resettinG and master control logic network means from said second stable state to said first stable state upon operation of said selector switch means, second feedback means coupled between said selector switch means and said input means for rendering said input means inoperative in response to selected conditions existing in said selector switch means, a plurality of input logic gate means coupled to said master control logic network means and to both said selector switch means and said control relay means for generating and enabling output to said control relay means and said selector switch means upon the occurence of a predetermined combination of signals from said plurality of input logic gate means, a flip-flop circuit coupled to said plurality of input logic gate means and triggered by said enabing output, and a switch coupled to said flip-flop circuit and said motor, said motor being mechanically coupled to said switch for mechanically actuating said switch and resetting said flip-flop.
 6. A control circuit as in claim 5, wherein: said first feedback means includes a NOR gate coupled to the output of said multiple input logic gate.
 7. A control circuit for a vending device comprising: input means for generating an activating signal in response to detection of a predetermined mechanical stimulus, master control logic network means coupled to said input means for switching from a first stable state to a second stable state in response to generation of said activating signal, vending stage control means including a plurality of substantially identical vending control circuits coupled to said master control logic network means for controlling the dispensing of items from said vending device, said vending stage control means being disabled when said master control logic network means is in said first stable state and enabled when said master control logic network means is in said second stable state, first feedback means coupled between said vending stage control means and said master control logic network means for resetting said master control logic network means from said second stable state to said first stable state upon operation of said vending stage control means, second feedback means coupled between said vending stage control and said means, second feedback means including a first switch means in each of said vending control circuits rendering said input means inoperative when items in said vending device are sold out, second switch means in each of said vending control circuits for rendering said input means inoperative during the occurence of a vending cycle, each said vending control circuits having a first logic gate coupled to corresponding first and second switches of said vending control circuit, each said vending control circuit having a second logic gate coupled to each first logic gate and to said input means for rendering said input means inoperative upon generation of appropriate combination of outputs from said switches.
 8. A solid state circuit for a vending device having a plurality of vending stations, comprising: electromagnetic means for preventing insertion of a coin into said vending device when all the vending stations are sold out or jammed, each vending station having a sold-out switch and a manually operable select switch and a vend motor and a drive circuit for the vend motor, each vending station having a first gate coupled to a corresponding select switch and a corresponding sold-out switch, a master control logic network coupled to each first gate and being coin activated to a first stable state sending an enabling signal to each first gate, each first gate being coupled to a drive circuit of each vending station, each said select switch being manually actuable to send an enabling signal to a corresponding first gate, each first gate being enabled by said logic network and a corresponding select switch to enable a cOrresponding drive circuit and to operate a corresponding vend motor, a unistable transfer switch in a first stable state connecting a corresponding drive circuit to a corresponding vend motor, the output of each vend motor being connected to a corresponding transfer switch, each transfer switch being thrown to an unstable state by operation of a corresponding vend motor to reset said corresponding drive circuit of an operating vent motor, each said transfer switch automatically resetting to its first stable state at completion of a vend cycle, each first gate receiving an inhibit signal from a corresponding sold-out switch activated because of an empty vend station, each sold-out switch being coupled to said electromagnetic means to activate said electromagnetic means when all the sold-out switches are activated to prevent insertion of a coin into said vending machine, and each transfer switch being coupled to said electromagnetic means and maintaining said electromagnetic means activated when all the transfer switches are in a jammed condition between their unstable and stable state to prevent insertion of a coin into said vending machine. 